Unit 1
Glossary
Accelerated 6
Area is the number of square units that cover a two-dimensional region without gaps or overlaps.
- The area of region A is 8 square units.
- The area of the shaded region of B is \(\frac12\) square unit.
Any side of a parallelogram or triangle can be chosen its base. The length of this side is also called the base.
A base is a specific face of a prism or pyramid.
A prism has 2 identical bases that are parallel. A pyramid has 1 base.
A prism or pyramid is named for the shape of its base.
The word compose means “put together.” To compose a shape, put figures together to make a new shape.
From an earlier course.
The word decompose means “take apart.” To decompose a shape, take it apart to make more than one new shape.
From an earlier course.
Each flat side of a polyhedron is called a face.
For example, a cube has 6 faces that are all squares.
The height is the shortest distance from the base of the shape to the opposite side (for a parallelogram) or to the opposite vertex (for a triangle).
The height can be shown in more than one place. It is always perpendicular to the chosen base.
A net is a two-dimensional figure that can be folded to make a three-dimensional figure.
Here is a net for a cube.
For each side of a triangle, there is 1 vertex that is not on that side. This is the opposite vertex.
Point \(A\) is the opposite vertex to side \(BC\).
A parallelogram is a type of quadrilateral that has 2 pairs of parallel sides.
Here are 2 examples of parallelograms.
From an earlier course.
A polygon is a closed, two-dimensional shape with straight sides that do not cross each other.
Figure \(ABCDE\) is an example of a polygon.
A polyhedron is a closed, three-dimensional shape with flat sides. When there is more than one polyhedron, they are called polyhedra.
Here are some drawings of polyhedra.
A prism is a type of polyhedron with 2 bases that are identical and parallel. The bases are connected by parallelograms.
Here are some drawings of prisms.
A pyramid is a type of polyhedron that has 1 base. All the other faces are triangles that meet at a single vertex.
Here are some drawings of pyramids.
A quadrilateral is a type of polygon that has 4 sides.
- A rectangle is an example of a quadrilateral.
- A pentagon is not a quadrilateral, because it has 5 sides.
From an earlier course.
A region is the space inside of a shape.
- Examples of two-dimensional regions are the inside of a circle and the inside of a polygon.
- Examples of three-dimensional regions are the inside of a cube and the inside of a sphere.